CN108928122B

CN108928122B - Piezoelectric device, liquid ejection head, and liquid ejection apparatus

Info

Publication number: CN108928122B
Application number: CN201810337041.8A
Authority: CN
Inventors: 山崎清夏; 田村博明
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2017-05-29
Filing date: 2018-04-16
Publication date: 2020-03-03
Anticipated expiration: 2038-04-16
Also published as: JP2018199290A; EP3450027A1; US20180342665A1; CN108928122A; EP3450027B1

Abstract

The present invention relates to a piezoelectric device, a liquid ejection head, and a liquid ejection apparatus that suppress the occurrence of cracks in a vibration plate. A piezoelectric device is provided with: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon base material having an anisotropy in which a Poisson's ratio differs depending on an in-plane direction, wherein in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, a Poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing a minimum vibration region is included in a range in which the Poisson's ratio in the crystal plane is not less than a minimum value but less than an average value.

Description

Piezoelectric device, liquid ejection head, and liquid ejection apparatus

Technical Field

The present invention relates to a technique for generating pressure fluctuations by a piezoelectric device.

Background

Conventionally, there has been proposed a liquid ejection head in which a pressure in a pressure chamber is varied by a piezoelectric device, and a liquid such as ink supplied to the pressure chamber is ejected from a nozzle. For example, patent document 1 discloses a technique of providing a piezoelectric device including a diaphragm constituting a wall surface (upper surface) of a pressure chamber and a piezoelectric element for vibrating the diaphragm for each pressure chamber. The active layer substrate (portion deformed by vibration) of the vibrating plate is made of a silicon substrate whose young's modulus changes according to the direction in the crystal plane. In patent document 1, the short-side direction of the vibrating plate is made to coincide with a direction in which the young's modulus of the vibrating plate in the short-side direction is smaller than the young's modulus of the vibrating plate in the long-side direction within the crystal plane, whereby the short-side direction of the vibrating plate is easily deformed, thereby improving the displacement characteristics of the vibrating plate.

However, not only the young's modulus but also the poisson's ratio has anisotropy depending on the crystal plane of the silicon substrate, and the poisson's ratio and the young's modulus are different in the manner of change due to the in-plane direction. Therefore, even if the direction of the vibrating plate is made to coincide with the in-plane direction in consideration of only the young's modulus, cracks (flaws) are likely to occur in the vibrating plate according to the poisson's ratio in the direction, and the piezoelectric device may be damaged.

Patent document 1: japanese laid-open patent publication No. 2002-67307

Disclosure of Invention

In view of the above, an object of the present invention is to suppress the occurrence of cracks in a vibration plate.

In order to solve the above problem, a piezoelectric device of the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon base material having an anisotropy in which a Poisson's ratio differs depending on an in-plane direction, wherein in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, the Poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing the vibration region is included in a range in which the Poisson's ratio in the crystal plane is not less than a minimum value and less than an average value. According to the above aspect, the poisson's ratio in the short axis direction, which affects the expansion and contraction in the long axis direction of the diaphragm, is suppressed to a small value that is equal to or greater than the minimum value and smaller than the average value. Therefore, even if the diaphragm is displaced in the direction of extension by the vibration of the piezoelectric element, the force with which the diaphragm attempts to contract in the long axis direction is reduced as compared with a case where the poisson's ratio in the short axis direction of the diaphragm is a large value higher than the average value, and therefore the amount of contraction in the long axis direction is reduced. In this way, by reducing the poisson's ratio in the short axis direction, the amount of contraction in the long axis direction is reduced, and the force pulling the vibration plate in the long axis direction is reduced, so for example, stress concentration at a portion (for example, an arm portion) of the vibration plate that contracts in the long axis direction is also relieved, and therefore, the occurrence of cracks in the vibration plate can be suppressed.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon base material having anisotropy in which Poisson ratios are different depending on directions within the crystal plane, the single crystal silicon base material being a base material having a {100} plane as a crystal plane, the vibration plate having a vibration region overlapping the pressure chamber in a plan view, the vibration plate having a Poisson ratio in a minor axis direction of a rectangle containing a minimum vibration region included therein, the vibration plate having a Poisson ratio within the crystal plane within a range of not less than a minimum value of the Poisson ratio within the crystal plane and less than 0.18065. According to the above aspect, the amount of contraction in the long axis direction of the diaphragm is smaller than in the case where the poisson's ratio is a large value such as greater than 0.18065. Therefore, the stress concentration in the portion of the vibration plate that contracts in the long axis direction is also relieved, and therefore the occurrence of cracks in the vibration plate can be suppressed.

In a preferred embodiment of the present invention, the poisson's ratio of the vibrating plate in the minor axis direction is included in a range of not less than the minimum value of poisson's ratios in the crystal plane and not more than 0.0864. According to the above aspect, even if a material having a poisson's ratio exceeding 0.0864 (for example, a material constituting the piezoelectric element or a material between the piezoelectric element) is laminated on the diaphragm, it is possible to suppress excessive deformation of the diaphragm caused by expansion and contraction of the laminated material. This makes it possible to prevent the diaphragm from being damaged by the expansion and contraction of the laminate material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, wherein the vibration plate has a crystal face of a single crystal silicon base material having anisotropy in which Poisson's ratio differs depending on an in-plane direction, the single crystal silicon base material is a base material having a (100) crystal face, and in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, an orientation of the Poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing a minimum vibration region is included in a range from an orientation [011] in the crystal plane, which is an orientation shifted by 21 degrees toward the crystal orientation [010] to an orientation shifted by 21 degrees toward the crystal orientation [001 ]. According to the above aspect, since the poisson's ratio of the diaphragm in the short axis direction can be reduced, the contraction amount in the long axis direction is reduced, and therefore, the occurrence of cracks in the diaphragm can be suppressed.

In a preferred embodiment of the present invention, the orientation of the poisson's ratio of the vibrating plate in the short axis direction is included in a range from an orientation shifted by 7 degrees toward the crystal orientation [010] to an orientation shifted by 7 degrees toward the crystal orientation [001] with respect to the crystal orientation [011] in the crystal plane. According to the above aspect, since the poisson's ratio can be reduced more easily than the material laminated on the diaphragm, unnecessary deformation of the diaphragm caused by expansion and contraction of the laminated material can be suppressed, and therefore the diaphragm can be made less likely to be damaged by expansion and contraction of the laminated material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon base material having anisotropy in which a Poisson's ratio differs depending on a direction in the crystal plane, the single crystal silicon base material being a base material having a crystal plane of (010), wherein in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, an orientation of the Poisson's ratio of the vibration plate in a minor axis direction of a smallest rectangle containing the vibration region is included in a range of an orientation shifted by 21 degrees toward the crystal orientation [ -100] to an orientation shifted by 21 degrees toward the crystal direction [001] with respect to the crystal orientation [ -101] in the crystal plane. According to the above aspect, the poisson's ratio of the vibration plate in the short axis direction can be reduced, and the contraction amount in the long axis direction becomes small, so that the occurrence of cracks in the vibration plate can be suppressed.

In a preferred embodiment of the present invention, the orientation of the poisson's ratio of the vibration plate in the minor axis direction is included in a range from an orientation shifted by 7 degrees toward the crystal orientation [ -100] to an orientation shifted by 7 degrees toward the crystal orientation [001] with respect to the crystal orientation [ -101] in the crystal plane. According to the above aspect, since the poisson's ratio can be reduced more easily than the material laminated on the diaphragm, unnecessary deformation of the diaphragm caused by expansion and contraction of the laminated material can be suppressed, and therefore the diaphragm can be made less likely to be damaged by expansion and contraction of the laminated material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon base material having anisotropy in which Poisson's ratio differs depending on an in-plane direction, the single crystal silicon base material being a base material having a (001) plane, wherein in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, an orientation of the Poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing a minimum vibration region is included in a range from an orientation shifted by 21 degrees toward a crystal orientation [010] to an orientation shifted by 21 degrees toward the crystal orientation [00-1] with respect to the crystal orientation [ -110] in the crystal plane. According to the above aspect, since the poisson's ratio of the diaphragm in the short axis direction can be reduced, the contraction amount in the long axis direction is reduced, and therefore, the occurrence of cracks in the diaphragm can be suppressed.

In a preferred embodiment of the present invention, the orientation of the poisson's ratio of the vibrating plate in the short axis direction is included in a range from an orientation shifted by 7 degrees toward crystal orientation [00-1] to an orientation shifted by 7 degrees toward crystal orientation [010] with respect to the crystal orientation [110] in the crystal plane. According to the above aspect, since the poisson's ratio can be reduced more easily than the material laminated on the diaphragm, unnecessary deformation of the diaphragm caused by expansion and contraction of the laminated material can be suppressed, and therefore the diaphragm can be made less likely to be damaged by expansion and contraction of the laminated material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibrating plate disposed between the pressure chamber and the piezoelectric element, the vibrating plate having a crystal plane of a single crystal silicon base material having anisotropy in which Poisson ratios are different depending on directions within the crystal plane, the single crystal silicon base material being a base material having a {110} plane as a crystal plane, the vibrating plate including a vibrating region in a vibrating region overlapping the pressure chamber in a plan view, the Poisson ratio in a minor axis direction of a rectangle having a smallest size and including the vibrating region being included in the vibrating region, the Poisson ratio in the crystal plane being in a range of not less than a minimum value and less than 0.24127. According to the above aspect, the amount of contraction in the long axis direction of the diaphragm is smaller than in the case where the poisson's ratio is a large value such as higher than 0.24127. Therefore, the stress concentration in the portion of the vibration plate that contracts in the long axis direction is also relieved, and therefore the occurrence of cracks in the vibration plate can be suppressed.

In a preferred embodiment of the present invention, the poisson's ratio in the minor axis direction is included in a range from the minimum value of poisson's ratio in the crystal plane to 0.1968 or less. According to the above aspect, even if a material having a poisson's ratio exceeding 0.1968 (for example, a material constituting the piezoelectric element or a material between the piezoelectric element) is laminated on the diaphragm, unnecessary deformation of the diaphragm caused by expansion and contraction of the laminated material can be suppressed. This makes it possible to prevent the diaphragm from being damaged by the expansion and contraction of the laminate material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon substrate having anisotropy in which a Poisson's ratio differs depending on an in-plane direction, the single crystal silicon substrate being a substrate having a (110) plane, wherein in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, an orientation of the Poisson's ratio of the vibration plate in a minor axis direction of a smallest rectangle including the vibration region is included in a range of an orientation shifted by 7 degrees from a crystal orientation [ -111] in the crystal plane toward [ -112] and an orientation shifted by 20 degrees toward [ -111] to an orientation shifted by 25 degrees toward [ -112 ]. According to the above aspect, the poisson's ratio of the diaphragm in the short axis direction can be reduced, and therefore the contraction amount in the long axis direction becomes small. Therefore, the stress concentration in the portion of the diaphragm that contracts in the longitudinal direction is also relieved, and therefore the occurrence of cracks in the diaphragm can be suppressed.

In a preferred mode of the present invention, the orientation of the poisson's ratio of the vibration plate in the short axis direction is included in a range from an orientation shifted by 7 degrees toward [ -112] from the crystal orientation [ -111] in the crystal plane to an orientation shifted by 13 degrees toward [ -111] to an orientation shifted by 15 degrees toward [ -112 ]. According to the above aspect, since the poisson's ratio can be reduced more easily than the material laminated on the diaphragm, and the excessive deformation of the diaphragm caused by the expansion and contraction of the laminated material can be suppressed, the diaphragm can be made less likely to be damaged by the expansion and contraction of the laminated material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; a vibration plate is arranged between a pressure chamber and a piezoelectric element, the vibration plate has a crystal face of a single crystal silicon base material with anisotropy that the Poisson's ratio differs according to the direction in the crystal face, the single crystal silicon base material is a base material with a (011) face, and in a vibration region overlapping the pressure chamber in a plan view in the vibration plate, the orientation of the Poisson's ratio of the vibration plate in the minor axis direction of a rectangle containing the smallest vibration region is included in a range from the orientation [1-11] in the crystal face to the orientation [1-12] shifted by 7 degrees, to the orientation [1-11] shifted by 20 degrees to the orientation [1-12] shifted by 25 degrees. According to the above aspect, the poisson's ratio of the diaphragm in the short axis direction can be reduced, and therefore the contraction amount in the long axis direction is reduced. Therefore, the stress concentration in the portion of the diaphragm that contracts in the longitudinal direction is also relieved, and therefore the occurrence of cracks in the diaphragm can be suppressed.

In a preferred embodiment of the present invention, the orientation of the poisson's ratio of the vibrating plate in the minor axis direction is included in a range from an orientation shifted by 7 degrees from the crystal orientation [1-11] in the crystal plane toward [1-12], to an orientation shifted by 13 degrees toward [1-11] to an orientation shifted by 15 degrees toward [1-12 ]. According to the above aspect, since the poisson's ratio can be reduced more easily than the material laminated on the diaphragm, and the excessive deformation of the diaphragm caused by the expansion and contraction of the laminated material can be suppressed, the diaphragm can be made less likely to be damaged by the expansion and contraction of the laminated material.

In order to solve the above problem, a piezoelectric device according to the present invention includes: a pressure chamber; a piezoelectric element; and a vibration plate disposed between the pressure chamber and the piezoelectric element, the vibration plate having a crystal plane of a single crystal silicon base material having anisotropy in which Poisson's ratio differs depending on an in-plane direction, the single crystal silicon base material being a base material having a (101) plane, wherein in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, an orientation of the Poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing a minimum vibration region is included in a range of an orientation shifted by 7 degrees toward [12-1] from a crystal orientation [11-1] in the crystal plane and an orientation shifted by 20 degrees toward [11-1] to an orientation shifted by 25 degrees toward [12-1 ]. According to the above aspect, since the poisson's ratio of the diaphragm in the short axis direction can be reduced, the amount of contraction in the long axis direction is reduced. Therefore, the stress concentration in the portion of the diaphragm that contracts in the longitudinal direction is also relieved, and therefore the occurrence of cracks in the diaphragm can be suppressed.

In a preferred embodiment of the present invention, the orientation of the poisson's ratio of the vibrating plate in the minor axis direction is included in a range from an orientation shifted by 7 degrees from the crystal orientation [11-1] in the crystal plane toward [12-1], to an orientation shifted by 13 degrees toward [11-1] to an orientation shifted by 15 degrees toward [12-1 ]. According to the above aspect, since the poisson's ratio can be reduced more easily than the material laminated on the diaphragm, unnecessary deformation of the diaphragm caused by expansion and contraction of the laminated material can be suppressed, and thus the diaphragm can be made less likely to be damaged by expansion and contraction of the laminated material.

In order to solve the above problem, a liquid discharge head according to the present invention includes the piezoelectric device according to any one of the above aspects, and discharges a liquid filled in a pressure chamber from a nozzle by vibrating a vibrating plate using a piezoelectric element to vary the pressure of the pressure chamber. According to the above aspect, a liquid ejection head including a piezoelectric device that can suppress the occurrence of cracks in the vibration plate can be provided.

In order to solve the above problem, a liquid discharge apparatus according to the present invention includes the piezoelectric device according to any one of the above aspects, and discharges a liquid filled in a pressure chamber from a nozzle by vibrating a vibrating plate using a piezoelectric element to change the pressure of the pressure chamber. According to the above aspect, a liquid ejecting apparatus including a piezoelectric device capable of suppressing the occurrence of cracks in the vibrating plate can be provided.

Drawings

Fig. 1 is a configuration diagram of a liquid ejecting apparatus according to a first embodiment of the present invention.

Fig. 2 is an exploded perspective view of the liquid ejection head.

Fig. 3 is a sectional view III-III of the liquid ejection head shown in fig. 2.

Fig. 4 is a sectional view and a plan view of the piezoelectric device.

Fig. 5 is a V-V sectional view of the piezoelectric device shown in fig. 4.

Fig. 6 is a graph showing an example of the anisotropy of the poisson's ratio in the (100) plane of the single-crystal silicon substrate.

Fig. 7 is a graph showing an example of the anisotropy of the poisson's ratio in the (110) plane of a single-crystal silicon substrate.

Fig. 8 is an enlarged cross-sectional view and a plan view of the piezoelectric device according to the second embodiment.

Fig. 9 is a cross-sectional view IX-IX of the piezoelectric device shown in fig. 8.

Fig. 10 is a sectional view of a piezoelectric device of a modification of the third embodiment.

Fig. 11 is an enlarged plan view of the piezoelectric device according to the fourth embodiment.

Fig. 12 is a sectional view XII-XII of the piezoelectric device shown in fig. 11.

Detailed Description

First embodiment

Fig. 1 is a configuration diagram illustrating a liquid discharge apparatus 10 according to a first embodiment of the present invention. The liquid ejecting apparatus 10 according to the first embodiment is an ink jet printing apparatus that ejects ink as an example of a liquid onto a medium 12. The medium 12 is typically a printing paper, but any printing object such as a resin film or a fabric may be used as the medium 12. As shown in fig. 1, a liquid container 14 for storing ink is fixed to the liquid ejecting apparatus 10. As the liquid container 14, for example, an ink cartridge that is detachable from the liquid ejecting apparatus 10, a bag-shaped ink pack formed of a flexible film, or an ink tank that can be replenished with ink is used. A plurality of inks different in color are stored in the liquid container 14.

As shown in fig. 1, the liquid ejecting apparatus 10 includes a control device 20, a transport mechanism 22, a moving mechanism 24, and a plurality of liquid ejecting heads 26. The control device 20 includes a Processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a memory circuit such as a semiconductor memory, and collectively controls each element of the liquid ejecting apparatus 10. The conveyance mechanism 22 conveys the medium 12 in the Y direction based on control performed by the control device 20.

The moving mechanism 24 reciprocates the plurality of liquid ejection heads 26 in the X direction based on control performed by the control device 20. The X direction is a direction intersecting (typically orthogonal to) the Y direction in which the medium 12 is conveyed. The moving mechanism 24 includes a carriage 242 on which the plurality of liquid ejection heads 26 are mounted, and an endless belt 244 to which the carriage 242 is fixed. Further, the liquid container 14 can be mounted on the carriage 242 together with the liquid ejection head 26.

The plurality of liquid discharge heads 26 discharge the ink supplied from the liquid tank 14 to the medium 12 from the plurality of nozzles (discharge holes) based on the control performed by the control device 20. The ink is ejected from each liquid ejection head 26 toward the medium 12 in parallel with the conveyance of the medium 12 by the conveyance mechanism 22 and the repeated reciprocating movement of the carriage 242, whereby a desired image is formed on the surface of the medium 12. Further, hereinafter, a direction perpendicular to an X-Y plane (e.g., a plane parallel to the surface of the medium 12) is denoted as a Z direction. The ejection direction (typically, the vertical direction) of the ink ejected from each liquid ejection head 26 corresponds to the Z direction.

Liquid ejection head

Fig. 2 is an exploded perspective view of any one of the liquid ejection heads 26, and fig. 3 is a sectional view III-III in fig. 2. As shown in fig. 2, the liquid ejection head 26 includes a plurality of nozzles N arranged in the Y direction. The nozzles N of the first embodiment are divided into a first row L1 and a second row L2. Although the positions of the nozzles N in the Y direction may be different between the first row L1 and the second row L2 (that is, arranged alternately or in a staggered manner), fig. 3 illustrates a configuration in which the positions of the nozzles N in the Y direction are matched between the first row L1 and the second row L2 for convenience of explanation. As shown in fig. 2, the liquid ejection head 26 has a structure in which elements related to the plurality of nozzles N in the first row L1 and elements related to the plurality of nozzles N in the second row L2 are arranged substantially in line symmetry.

As shown in fig. 2 and 3, the liquid ejection head 26 includes a flow path substrate 32. The flow path substrate 32 is a plate-like member including a surface F1 and a surface F2. The surface F1 is a surface on the positive side in the Z direction (surface on the medium 12 side), and the surface F2 is a surface on the opposite side (negative side in the Z direction) to the surface F1. The pressure generating unit 35 and the case member 40 are provided on the surface F2 of the flow path substrate 32, and the nozzle plate 52 and the flexible substrate 54 are provided on the surface F1. The respective elements of the liquid ejection head 26 are generally plate-like members elongated in the Y direction like the flow path substrate 32, and are bonded to each other using an adhesive, for example. The direction in which the flow channel substrate 32 and the pressure chamber substrate 34 are stacked may be grasped as the Z direction.

The pressure generating unit 35 is an element for generating pressure fluctuation for ejecting ink from the nozzles N. The pressure generating unit 35 of the present embodiment is configured by bonding a first substrate a including the pressure chamber substrate 34 and the piezoelectric device 39, a second substrate B including the wiring connection substrate (protective substrate) 38, and the driver IC 62. The piezoelectric device 39 is composed of a pressure chamber C, which will be described later, formed on the pressure chamber substrate 34, a piezoelectric element 37, and a vibrating plate 36 disposed between the pressure chamber C and the piezoelectric element 37, and is an element for generating pressure fluctuation caused by vibration in the pressure chamber C. The pressure generating section 35 and the piezoelectric device 39 will be described in detail later.

The nozzle plate 52 is a plate-like member in which a plurality of nozzles N are formed, and is provided on the surface F1 of the flow path substrate 32 with an adhesive, for example. Each nozzle N is a through-hole through which ink passes. The nozzle plate 52 of the first embodiment is manufactured by processing a single crystal silicon (Si) base material (silicon substrate) by a semiconductor manufacturing technique. However, a known material or a known manufacturing method may be arbitrarily used for manufacturing the nozzle plate 52.

The flow path substrate 32 is a plate-like member for forming a flow path of ink. As shown in fig. 2 and 3, the flow path substrate 32 is formed with a space RA, a plurality of supply flow paths 322, and a plurality of communication flow paths 324 for each of the first row L1 and the second row L2. The space RA is an elongated opening along the Y direction in a plan view (i.e., in the Z direction), and the supply flow path 322 and the communication flow path 324 are through holes formed for each nozzle N. The plurality of supply channels 322 are arranged in the Y direction, and the plurality of communication channels 324 are also arranged in the Y direction. As shown in fig. 3, an intermediate flow path 326 extending over the plurality of supply flow paths 322 is formed on a surface F1 of the flow path substrate 32. The intermediate flow passage 326 is a flow passage that connects the space RA and the flow passages of the plurality of supply flow passages 322. On the other hand, the communication flow passage 324 communicates with the nozzle N.

The wiring connection substrate 38 in fig. 2 and 3 is a plate-like member for protecting the plurality of piezoelectric elements 37, and is provided on a surface (a surface on the opposite side to the pressure chambers C) of the diaphragm 36. Although the material and the manufacturing method of the wiring connection substrate 38 are arbitrary, the wiring connection substrate 38 may be formed by processing a single crystal silicon (Si) base material (silicon substrate) by a semiconductor manufacturing technique, similarly to the flow path substrate 32 and the pressure chamber substrate 34. As shown in fig. 2 and 3, a drive IC62 is provided on a surface (hereinafter referred to as a "mounting surface") of the wiring connection board 38 opposite to the surface (hereinafter referred to as a "bonding surface") on the diaphragm 36 side. The driver IC62 is a substantially rectangular IC chip on which a driver circuit is mounted, and the driver circuit drives each piezoelectric element 37 by generating and supplying a drive signal based on control performed by the control device 20. On the mounting surface of the wiring connection substrate 38, a wiring 384 connected to an output terminal of a drive signal (drive voltage) of the drive IC62 is formed for each piezoelectric element 37. On the mounting surface of the wiring connection substrate 38, a wiring 385 connected to an output terminal of the base voltage of the driver IC62 (base voltage of the drive signal of the piezoelectric element) is formed so as to be continuous in the Y direction along the arrangement of the piezoelectric elements 37.

The case member 40 shown in fig. 2 and 3 is a case for storing ink supplied to the plurality of pressure chambers C (and further the plurality of nozzles N). The front surface of the case member 40 in the Z direction is fixed to a surface F2 of the flow path substrate 32 with an adhesive, for example. As shown in fig. 2 and 3, a groove-like recess 42 extending in the Y direction is formed in the surface of the case member 40 on the Z direction front side. The wiring connection board 38 and the drive IC62 are housed inside the recess 42. The case member 40 is formed of a different material from the flow path substrate 32 and the pressure chamber substrate 34. The case member 40 can be manufactured by injection molding of a resin material, for example. However, any known material and method may be used for manufacturing the case member 40. As the material of the case member 40, for example, synthetic fibers or a resin material is preferable.

As shown in fig. 3, in case member 40, a space RB is formed for each of first row L1 and second row L2. The space RB of the case member 40 and the space RA of the flow path substrate 32 communicate with each other. The space formed by the space RA and the space RB functions as a liquid storage chamber (reservoir) R that stores ink supplied to the plurality of pressure chambers C. The liquid reservoir R is a common liquid chamber extending over the plurality of nozzles N. An inlet 43 for introducing the ink supplied from the liquid container 14 into the liquid storage chamber R is formed in each of the first row L1 and the second row L2 on the surface of the case member 40 on the side opposite to the flow path substrate 32.

The ink supplied from the liquid container 14 to the inlet 43 is stored in the space RB and the space RA of the liquid storage chamber R. The ink stored in the liquid storage chamber R is branched from the intermediate flow path 326 into the plurality of supply flow paths 322, and is supplied and filled in the respective pressure chambers C in parallel.

As shown in fig. 2, a flexible substrate 54 is provided on the surface F1. The flexible substrate 54 is a flexible thin film that absorbs pressure fluctuations of the ink in the liquid storage chamber R. As shown in fig. 3, the flexible substrate 54 is provided on the surface F1 of the flow path substrate 32 so as to close the space RA of the flow path substrate 32, the intermediate flow path 326, and the plurality of supply flow paths 322, and forms a wall surface (specifically, a bottom surface) of the liquid storage chamber R.

The pressure generating section 35 shown in fig. 3 is formed by laminating a first substrate a, a second substrate B, and a drive IC 62. The first substrate a is a substrate including the pressure chamber substrate 34, the vibration plate 36, and the plurality of piezoelectric elements 37, and the second substrate B is a substrate including the wiring connection substrate 38.

The pressure chamber substrate 34 is a plate-like member in which a plurality of openings 342 constituting the pressure chambers C are formed for each of the first row L1 and the second row L2, and is provided on the surface F2 of the flow path substrate 32 with an adhesive, for example. The plurality of openings 342 are aligned in the Y direction. Each opening 342 is an elongated through-hole formed for each nozzle N and extending along the X direction in a plan view. Similarly to the nozzle plate 52 described above, the flow path substrate 32 and the pressure chamber substrate 34 are manufactured by processing a single crystal silicon (Si) base material (silicon substrate) by a semiconductor manufacturing technique. However, any known material and method may be used for manufacturing the flow channel substrate 32 and the pressure chamber substrate 34. A piezoelectric device 39 is provided on the surface of the pressure chamber substrate 34 on the side opposite to the flow channel substrate 32.

Piezoelectric device

Fig. 4 is an enlarged cross-sectional view and a plan view of the piezoelectric device 39. The cross-sectional view of fig. 4 (the upper side view of fig. 4) is a view obtained by cutting the piezoelectric device 39 along the X-Z plane, and the plan view of fig. 4 (the lower side view of fig. 4) is a view of the piezoelectric device 39 as viewed from the Z direction. Fig. 5 is a V-V sectional view of the piezoelectric device 39 shown in fig. 4. As shown in fig. 4 and 5, the piezoelectric device 39 includes pressure chambers C, a piezoelectric element 37, and a vibrating plate 36, and the vibrating plate 36 is vibrated by the piezoelectric element 37, thereby generating pressure fluctuations in the pressure chambers C. The shape of the inner periphery 345 of the pressure chamber C in fig. 4 and the shape of the piezoelectric element 37 are rectangular shapes including a major axis along the X direction and a minor axis shorter than the major axis and along the Y direction in a plan view. The shape of the inner periphery 345 of the pressure chamber C is the shape of the inner periphery 345 of the side wall 344 of the pressure chamber C when viewed from the Z direction in plan, and defines the vibration region P of the vibration plate 36. The vibration region P of the vibration plate 36 is a region of the vibration plate 36 that overlaps the pressure chamber C in a plan view, and is a region that constitutes a wall surface (upper surface) of the pressure chamber C.

As shown in fig. 2 and 3, the surface F2 of the flow path substrate 32 and the diaphragm 36 face each other with a space therebetween inside each opening 342. Inside the opening 342, a space between the surface F2 of the flow path substrate 32 and the vibrating plate 36 functions as a pressure chamber C for applying pressure to the ink filled in the space. The pressure chamber C is formed separately for each nozzle N. As shown in fig. 2, the plurality of pressure chambers C (openings 342) are aligned in the Y direction for each of the first row L1 and the second row L2. Any one of the pressure chambers C communicates with the space RA via the supply flow passage 322 and the intermediate flow passage 326, and communicates with the nozzle N via the communication flow passage 324.

As shown in fig. 2 to 5, on the surface of the diaphragm 36 on the opposite side of the pressure chamber C, a plurality of piezoelectric elements 37 corresponding to different nozzles N are provided for each of the first row L1 and the second row L2. The piezoelectric element 37 is a pressure generating element that is deformed by the supply of a drive signal to generate a pressure in the pressure chamber C. The plurality of piezoelectric elements 37 are arranged along the Y direction so as to correspond to the respective pressure chambers C.

The piezoelectric element 37 is a laminate in which a piezoelectric layer is interposed between a first electrode and a second electrode that face each other. By applying a voltage between the first electrode and the second electrode, the piezoelectric layer sandwiched between the first electrode and the second electrode is subjected to piezoelectric strain and displaced. Therefore, the piezoelectric element 37 is a portion where the first electrode and the second electrode overlap with the piezoelectric layer. The pressure in the pressure chamber C fluctuates due to the vibration of the vibration plate 36 in conjunction with the piezoelectric strain of the piezoelectric layer. Further, a close contact layer for securing close contact force may be provided between the piezoelectric element 37 and the diaphragm 36. That is, the piezoelectric element 37 need not be provided directly on the surface of the diaphragm 36, but may be provided on the surface of the diaphragm 36 with an adhesion layer interposed therebetween. As the adhesion layer, zirconium oxide, titanium oxide, silicon oxide, or the like can be used.

As shown in fig. 4 and 5, the vibrating plate 36 is a plate-like member that can elastically vibrate. The vibration plate 36 of the present embodiment is made of a single crystal silicon substrate having anisotropy in which the poisson ratio differs depending on the in-plane direction, and the surface of the vibration plate 36 is made of a crystal plane of the single crystal silicon substrate. However, the crystal of the single crystal silicon base material is not limited to exist on the surface of the vibration plate 36, and may be at least the surface of the vibration plate 36. For example, when the vibration plate 36 is formed by laminating a plurality of materials, the laminated material may contain a crystal of a single crystal silicon substrate. The diaphragm 36 is joined to the side wall 344 of the pressure chamber C (the pressure chamber substrate 34) in a stacked manner, and forms a wall surface (specifically, an upper surface) intersecting the side wall 344 of the pressure chamber C. As described above, the region of the vibration plate 36 that overlaps the pressure chamber C in plan view (the region that constitutes the upper surface of the pressure chamber C) is the vibration region P that is vibrated by the piezoelectric element 37.

The diaphragm 36 includes: an active portion 362a overlapping the piezoelectric element 37 in a plan view (when viewed from the Z direction), a fixed portion 362C overlapping the side wall 344 of the pressure chamber C in a plan view, and an arm portion 362b between the active portion 362a and the fixed portion 362C. The active portion 362a is a portion that vibrates in linkage with the piezoelectric strain of the piezoelectric layer 373. The arm portion 362b is a portion that supports the movable portion 362 a. The active portion 362a and the arm portion 362b constitute the vibration region P.

The vibration region P of the present embodiment has the same shape as the pressure chamber C in a plan view, and is a rectangle having a major axis along the X direction and a minor axis shorter than the major axis and along the Y direction. Hereinafter, the long axis of the rectangle along the X direction is referred to as the long axis Gx of the vibration region P, and the short axis of the rectangle along the Y direction is referred to as the short axis Gy of the vibration region P. The shape of the vibration region P may be other than a rectangle such as an ellipse or a rhombus. When the vibration region P has a shape other than a rectangle, the minor axis of the smallest rectangle containing the vibration region P is the minor axis Gy of the vibration region P, and the major axis of the smallest rectangle containing the vibration region P is the major axis Gx of the vibration region P. In the present embodiment, the shape of the vibration region P is matched to the smallest rectangle containing the vibration region P.

In the piezoelectric device 39 having such a configuration, as shown by the broken lines in fig. 4 and 5, the active portion 362a of the vibration region P of the vibration plate 36 is displaced in the Z direction H due to the piezoelectric strain of the piezoelectric element 37. In this case, even if the same displacement H occurs in the active portion 362a, the arm portion 362b in the Y direction (direction of the short axis Gy) shown in the cross-sectional view of fig. 5 is deformed so as to draw a steeper curve than the arm portion 362b in the X direction (direction of the long axis Gx) shown in the cross-sectional view of fig. 4. In the diaphragm 36, the direction of the short axis Gy deformed in a steep curve is greatly extended, and the direction of the long axis Gx is contracted in accordance with this. The active portion 362a and its vicinity overlapping the piezoelectric element 37 also extend in the direction of the long axis Gx in a plan view, but contract in the other direction of the long axis Gx (a part of the arm portion 362 b), thereby forming a convex shape on the pressure chamber C side.

In this case, for example, since the young's modulus varies depending on the crystal plane of the silicon substrate in accordance with the direction in the crystal plane, it is considered that the short axis Gy of the vibration plate 36 is aligned with the direction in the crystal plane in which the young's modulus is low, whereby the vibration plate 46 can be easily deformed in the direction of the short axis Gy in the Z direction, and thus the displacement characteristics of the vibration plate 36 can be improved.

However, not only the young's modulus but also the poisson's ratio has anisotropy depending on the crystal plane of the single crystal silicon base material, and the poisson's ratio and the young's modulus are different in the manner of change due to the in-plane direction. Therefore, even if the direction of the vibration plate 36 is aligned with the in-plane direction in consideration of only the young's modulus, cracks (flaws) are likely to occur in the vibration plate 36 depending on the poisson's ratio in that direction.

Fig. 6 is a graph showing an example of anisotropy of poisson's ratio and young's modulus in a (100) plane of a single crystal silicon substrate having a (100) plane (a plane perpendicular to the plane is oriented to [100 ]). In fig. 6, a graph of the anisotropy of poisson's ratio is shown by a solid line, and a graph of the anisotropy of young's modulus is shown by a broken line. FIG. 6 is a polar plot, with the further away from the center the greater the Young's modulus or Poisson's ratio.

As shown in fig. 6, the poisson's ratio in the (100) plane of the single-crystal silicon substrate having the (100) plane has four-lobed anisotropy, and the young's modulus has a substantially square anisotropy. As shown in fig. 6, the anisotropy of poisson's ratio is different from the anisotropy of young's modulus, and for example, the young's modulus is the smallest in the crystal orientation [001], while the poisson's ratio is the largest. Therefore, if the direction of the vibration plate 36 is made to coincide with the crystal orientation [001] for example in order to reduce the young's modulus, the poisson's ratio becomes large, and therefore cracks (cracks) may easily occur in the vibration plate 36, and the piezoelectric device 39 may be damaged.

As described above, when the diaphragm 36 is deformed by the piezoelectric element 36, the direction of the short axis Gy is greatly extended, and the direction of the long axis Gx is contracted in accordance with the extension. The active portion 362a and its vicinity extend in the direction of the long axis Gx, but the other portion (a part of the arm portion 362 b) in the direction of the long axis Gx contracts. In this case, if it is assumed that poisson in the direction of the short axis Gy is large, the amount of contraction of the portion contracted in the direction of the long axis Gx becomes large, and therefore the force pulling the vibration plate 36 in the direction of the long axis Gx increases. Therefore, stress concentration occurs in a part of the arm portion 362b that contracts in the direction of the long axis Gx (for example, a boundary between the diaphragm 36 and the pressure chamber C, a boundary between the diaphragm 36 and the piezoelectric element 37, and the like in a plan view), and cracks are likely to occur.

Therefore, in the present embodiment, a method is adopted in which the poisson's ratio in the direction of the short axis Gy of the vibration plate 36 is included in a range of not less than the minimum value of poisson's ratios in the crystal plane and less than the average value. The average value here may be, for example, an average value calculated by dividing a value obtained by adding the minimum value and the maximum value of the poisson's ratio in the crystal plane by 2, or an average value calculated by dividing a value obtained by adding a plurality of sampled values of the poisson's ratio in the crystal plane by the number of the sampled values. With such a configuration, the poisson's ratio in the direction of the short axis Gy, which affects the expansion and contraction in the direction of the long axis Gx of the diaphragm 36, is suppressed to a small value that is equal to or greater than the minimum value and smaller than the average value. Therefore, even if the diaphragm 36 is displaced in the extending direction by the vibration of the piezoelectric element 37, the force with which the diaphragm 36 attempts to contract in the direction of the long axis Gx becomes weaker than in the case where the poisson's ratio in the direction of the short axis Gy of the diaphragm 36 is a large value such as a value higher than the average value, and therefore the amount of contraction in the direction of the long axis Gx becomes small. In this way, by reducing the poisson's ratio in the direction of the short axis Gy, the amount of contraction in the direction of the long axis Gx is reduced, and the force pulling the vibration plate 36 in the direction of the long axis Gx is reduced, so for example, stress concentration at a part of the arm portion 362b of the vibration plate 36 that contracts in the direction of the long axis Gy (for example, a boundary between the vibration plate 36 and the pressure chamber C, a boundary between the vibration plate 36 and the piezoelectric element 37, and the like in a plan view) is also alleviated, and therefore, occurrence of cracks in the vibration plate 36 can be suppressed.

Specifically, in the (100) plane of the single-crystal silicon base material shown in fig. 6, the minimum value of the poisson's ratio was approximately 0.0664, and the average value of the poisson's ratio was approximately 0.18065. Therefore, the poisson ratio of the vibration plate 36 in the direction of the short axis Gy can be expressed as a range of 0.18065 or more and less than the minimum value of the poisson ratio in the (100) plane. Further, the orientation Dm in the (100) plane shown in fig. 6 having the minimum poisson's ratio is the crystal orientation [011], and the orientation with the average poisson's ratio is the orientation D11 shifted by 21 degrees from the crystal orientation [011] toward the crystal orientation [010] and the orientation D11 ' shifted by 21 degrees from the crystal orientation [011] toward the crystal orientation [001 ]. Therefore, the range of the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy of the first embodiment described above can also be expressed as a range from the orientation D11 to the orientation D11' with respect to the orientation Dm.

As shown in fig. 6, the diaphragm 36 of the first embodiment is manufactured using a silicon single crystal wafer having a crystal plane of (100). Specifically, the diaphragm 36 of the first embodiment can be manufactured by cutting out the diaphragm 36 from the single crystal silicon wafer while aligning the direction of the short axis Gy of the diaphragm 36 with the crystal orientation in the crystal plane so that the poisson's ratio in the direction of the short axis Gy of the diaphragm 36 is included in a range (a range from the orientation D11 to the orientation D11 ' in fig. 6) in which the poisson's ratio in the crystal plane of the single crystal silicon wafer is not less than the minimum value but less than the average value.

As described above, from the viewpoint of suppressing the occurrence of cracks in the vibration plate 36, it is most preferable to set the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy of the first embodiment to the minimum value. Therefore, when the crystal plane of the single crystal silicon substrate having the (100) plane as the crystal plane shown in fig. 6 is set as the surface (upper surface) of the vibration plate 36, it is most effective to match the direction of the minor axis Gy of the vibration plate 36 with the orientation Dm.

Further, expansion and contraction of the material laminated on the diaphragm 36 may affect the displacement H of the diaphragm 36. For example, in the present embodiment, since the piezoelectric element 37 is laminated on the diaphragm 36, the displacement H of the diaphragm 36 may be affected by the expansion and contraction of the laminated material depending on the poisson's ratio in the direction of the short axis Gy of the material constituting the piezoelectric element 37 (for example, the material of the first electrode formed on the surface of the diaphragm 36). In addition, when a zirconium oxide film or a silicon oxide film is formed between the piezoelectric element 37 and the vibrating plate 36, the displacement H of the vibrating plate 36 may be affected by the expansion and contraction of the laminated material. If the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy is smaller than that of the laminate, the displacement H of the vibration plate 36 can be made less susceptible to the expansion and contraction of the laminate.

Therefore, in the first embodiment, the poisson's ratio of the vibration plate 36 in the direction of the minor axis Gy is preferably 0.1 to 0.2%, and if a margin is added thereto, the preferable range can be set to a range of not less than the minimum value and not more than 30% of the minimum value, and by adopting this, the influence of the laminated material laminated on the vibration plate 36 can be made less likely. In the single-crystal silicon substrate having a crystal plane of (100) shown in fig. 6, the value corresponding to a minimum poisson's ratio distance of 30% is approximately 0.0864. Therefore, in the first embodiment, a range in which the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy is not less than the minimum value and not more than 0.0864 is a preferable range. Accordingly, even if a material having a poisson's ratio exceeding 0.0864 in the direction of the minor axis Gy of the diaphragm 36 is laminated on the diaphragm 36, unnecessary deformation of the diaphragm 36 caused by expansion and contraction of the laminated material can be suppressed. In the above preferred range, a mode is adopted in which the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy is smaller than that of the laminated material. This makes it difficult for the displacement of the diaphragm 36 to be affected by the expansion and contraction of the laminate, and therefore, the diaphragm 36 can be prevented from being damaged by the expansion and contraction of the laminate.

The orientation of the minimum value of the poisson ratio in the (100) plane shown in fig. 6 is orientation Dm, and the orientations having a poisson ratio distance of 30% from the minimum value are orientation D12 shifted by 7 degrees toward crystal orientation [010] with respect to crystal orientation [011] and orientation D12' shifted by 7 degrees toward crystal orientation [001] with respect to crystal orientation [011 ]. Therefore, the above-described preferable range of the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy can also be expressed as a range from the orientation D12 to the orientation D12' with respect to the orientation Dm.

In the present embodiment, a case where the crystal plane (100) of the single crystal silicon base material is set as the surface (upper surface) of the vibration plate 36 is exemplified, but since the single crystal silicon is a cubic system, the configuration of the present embodiment can be applied even when the crystal plane equivalent to the crystal plane (100), that is, the (010) plane or the (001) plane is set as the surface (upper surface) of the vibration plate 36. Even if the (010) plane or the (001) plane is used as the crystal plane, the poisson ratio and the young's modulus have the shapes shown in fig. 6. However, when the crystal plane is a (010) plane, 3 crystal orientations [010], [011], [001] which are the reference in fig. 6 are applied by replacing the crystal orientations [ -100], [ -101], [001], respectively. When the crystal plane is the (001) plane, the crystal orientations [010], [011], [001] in fig. 6 are respectively replaced with the crystal orientations [010], [ -110], [ -100 ]. Thus, the crystal planes (100), (010), and (001) are equivalent, and the group of these planes can be collectively referred to as the crystal plane {100 }.

Second embodiment

A second embodiment of the present invention will be explained. In the following description, the same elements as those in the first embodiment in operation and function are used throughout the description of the first embodiment, and detailed description thereof will be omitted as appropriate. Although the case where the vibration plate 36 is formed of a single crystal silicon substrate having a crystal plane of (100) plane is exemplified in the first embodiment, the case where the vibration plate 36 is formed of a single crystal silicon substrate having a crystal plane of (110) plane (a crystal plane perpendicular to the crystal plane is oriented to [110]) is exemplified in the second embodiment.

Fig. 7 is a graph showing an example of the anisotropy of the poisson's ratio in the (110) plane and the young's modulus of a single crystal silicon substrate whose crystal plane is the (110) plane. In fig. 7, a graph of the anisotropy of poisson's ratio is shown by a solid line, and a graph of the anisotropy of young's modulus is shown by a broken line. FIG. 7 is a polar plot, with the further away from the center the greater the Young's modulus or Poisson's ratio.

As shown in fig. 7, the poisson's ratio in the (110) plane of the single-crystal silicon substrate has four-lobed anisotropy, and the young's modulus has a substantially rectangular anisotropy. As shown in fig. 7, the anisotropy of poisson's ratio is different from the anisotropy of young's modulus, and is also different from the shape of fig. 6. Therefore, even if the direction of the vibration plate 36 is aligned with the in-plane direction of the single crystal silicon substrate having the (110) plane in consideration of only the young's modulus, cracks are likely to occur in the vibration plate 36 depending on the poisson's ratio in the direction.

Therefore, similarly to the first embodiment, in the second embodiment, the poisson's ratio in the direction of the minor axis Gy of the vibration plate 36 is included in a range of not less than the minimum value of the poisson's ratios in the crystal plane and less than the average value. Specifically, in the (110) plane of the single crystal silicon substrate shown in fig. 7, the minimum value of the poisson's ratio is approximately 0.1514, and the average value of the poisson's ratio is approximately 0.24127. Therefore, the poisson ratio of the vibration plate 36 in the direction of the short axis Gy can be expressed in a range of 0.24127 or more and less than the minimum value of the poisson ratio in the (110) plane. In addition, orientation Dm, which is the minimum value of the poisson's ratio in the (110) plane shown in fig. 7, is an orientation shifted by 7 degrees from crystal orientation [ -111] toward [ -112], and the orientation having the average value of the poisson's ratio is orientation D21 shifted by 20 degrees toward crystal orientation [ -111] with respect to orientation Dm and orientation D21 ' shifted by 25 degrees toward crystal orientation [ -112] with respect to orientation Dm. Therefore, the range of the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy of the second embodiment described above can also be expressed as a range from the orientation D21 to the orientation D21' with respect to the orientation Dm.

According to the second embodiment, as in the first embodiment, the poisson's ratio in the direction of the short axis Gy, which affects the expansion and contraction in the direction of the long axis Gx of the diaphragm 36, is suppressed to a small value that is equal to or greater than the minimum value and smaller than the average value. Therefore, even if the diaphragm 36 is displaced in the extending direction by the vibration of the piezoelectric element 37, the force with which the diaphragm 36 attempts to contract in the long axis direction is reduced as compared with a case where the poisson's ratio in the short axis Gy direction of the diaphragm 36 is a large value such as a value higher than the average value, and therefore the amount of contraction in the long axis Gx direction is reduced. As described above, by reducing the poisson's ratio in the direction of the short axis Gy, the amount of contraction in the direction of the long axis Gx is reduced, and the force pulling the vibration plate 36 in the direction of the long axis Gx is reduced, so that, for example, stress concentration at a part of the arm portion 362b of the vibration plate 36 that contracts in the direction of the long axis Gy (for example, a boundary between the vibration plate 36 and the pressure chamber C, a boundary between the vibration plate 36 and the piezoelectric element 37, and the like in a plan view) is also alleviated, and therefore, occurrence of cracks in the vibration plate 36 can be suppressed.

As shown in fig. 7, the vibration plate 36 of the second embodiment is manufactured using a single crystal silicon wafer having a crystal plane of (110) plane. Specifically, the diaphragm 36 of the second embodiment can be manufactured by cutting out the diaphragm 36 from the single crystal silicon wafer while aligning the direction of the short axis Gy of the diaphragm 36 with the crystal orientation in the crystal plane so that the poisson's ratio in the direction of the short axis Gy of the diaphragm 36 is included in a range (a range from the orientation D21 to the orientation D21 ' in fig. 7) in which the poisson's ratio in the crystal plane of the single crystal silicon wafer is not less than the minimum value but less than the average value.

As described above, from the viewpoint of suppressing the occurrence of cracks in the vibration plate 36, it is most preferable to set the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy of the second embodiment to the minimum value. Therefore, when the crystal plane of the single crystal silicon substrate having the (110) plane as the crystal plane shown in fig. 7 is set as the surface (upper surface) of the vibration plate 36, it is most effective to match the direction of the minor axis Gy of the vibration plate 36 with the orientation Dm.

In the second embodiment, the poisson's ratio of the vibration plate 36 in the direction of the minor axis Gy is preferably 0.1 to 0.2%, and if a margin is added to this, the preferable range can be set to a range of not less than the minimum value and not more than 30% of the minimum value, and by adopting this, the influence of the laminated material laminated on the vibration plate 36 can be made less likely. In the single crystal silicon substrate having the crystal plane (110) as shown in fig. 7, the value of the poisson's ratio relative to the minimum value of 30% is approximately 0.1968. Therefore, in the second embodiment, a range in which the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy is not less than the minimum value and not more than 0.1968 is a preferable range. Accordingly, even if a material having a poisson's ratio exceeding 0.1968 in the direction of the minor axis Gy of the diaphragm 36 is laminated on the diaphragm 36, unnecessary deformation of the diaphragm 36 caused by expansion and contraction of the laminated material can be suppressed. In the above preferred range, a mode is adopted in which the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy is smaller than that of the laminated material. This makes it difficult for the displacement of the diaphragm 36 to be affected by the expansion and contraction of the laminate, and therefore, the diaphragm 36 can be prevented from being damaged by the expansion and contraction of the laminate.

The orientation of the minimum value of the poisson ratio in the (110) plane shown in fig. 7 is orientation Dm, and the orientation with a poisson ratio of 30% from the minimum value is orientation D22 shifted by 13 degrees toward crystal orientation [ -111] with respect to orientation Dm and orientation D22' shifted by 15 degrees toward [ -112] with respect to orientation Dm. Therefore, the above-described preferable range of the poisson's ratio of the vibration plate 36 in the direction of the short axis Gy can also be expressed as a range from the orientation D22 to the orientation D22' with respect to the orientation Dm.

In the present embodiment, the case where the crystal plane (110) of the single crystal silicon base material is the surface (upper surface) of the vibration plate 36 is exemplified, but since the single crystal silicon is a cubic system, the structure of the present embodiment can be applied even when the crystal plane equivalent to the crystal plane (110), that is, the (011) plane or the (101) plane is the surface (upper surface) of the vibration plate 36. Even if the crystal plane is the (011) plane or the (101) plane, the poisson ratio and the young's modulus have the shapes shown in fig. 7. However, in the case where the crystal plane is the (011) plane, the crystal orientations [1-11], [1-12], [100], [21-1], [11-1], [01-1] and [ -11-1] are used instead of the 7 crystal orientations [ 111], [ -112], [001], [1-12], [1-11], [1-10] and [1-1-1] which are the references in fig. 7, respectively. In addition, in the case where the crystal plane is the (101) plane, the crystal orientations of fig. 7 [ -111], [ -112], [001], [1-12], [1-11], [1-10], [1-1-1] are respectively replaced with crystal orientations [11-1], [12-1], [010], [ -121], [ -1-11], [ -101], [ -1-11] and the like. As such, the crystal planes (110), (011), and (101) are equivalent, and these plane groups can be collectively referred to as the crystal plane {110 }.

Third embodiment

A third embodiment of the present invention will be explained. In the third embodiment, a specific configuration example of the piezoelectric element 37 of the piezoelectric device 39 according to the first and second embodiments will be described. Fig. 8 is an enlarged sectional view and a plan view of the piezoelectric device 39 according to the third embodiment, and corresponds to fig. 4. The cross-sectional view of fig. 8 (the upper side view of fig. 8) is a view obtained by cutting the piezoelectric device 39 along the X-Z plane, and the plan view of fig. 8 (the lower side view of fig. 8) is a view of the piezoelectric device 39 as viewed from the Z direction. Fig. 9 is an IX-IX cross-sectional view of the piezoelectric device 39 shown in fig. 8.

As shown in the cross-sectional view of fig. 8 and the cross-sectional view of fig. 9, the piezoelectric element 37 according to the third embodiment is a laminated body in which a piezoelectric layer 373 is interposed between a first electrode 371 and a second electrode 372 that face each other. In the piezoelectric element 37 of fig. 8, a voltage is applied between the first electrode 371 and the second electrode 372, and thereby the piezoelectric layer 373 sandwiched between the first electrode 371 and the second electrode 372 is subjected to piezoelectric strain and displaced. Therefore, in the structure of fig. 8, a portion where the first electrode 371, the second electrode 372, and the piezoelectric layer 373 overlap in a plan view corresponds to the piezoelectric element 37 of fig. 4. The pressure in the pressure chamber C fluctuates due to the vibration of the vibration plate 36 in conjunction with the piezoelectric strain of the piezoelectric layer 373.

The first electrode 371 is formed individually for each piezoelectric element 37 (each nozzle N) on the surface of the vibration plate 36. Each of the first electrodes 371 is an electrode extending in the Y direction. Each first electrode 371 is connected to the driver IC62 via a lead electrode 371A drawn out to the outside of the piezoelectric layer 373. The lead electrodes 371A are electrically connected to each other, and the first electrodes 371 become common electrodes of the plurality of piezoelectric elements 37. The material of the first electrode 371 is preferably a material which is not oxidized and can maintain conductivity when the piezoelectric layer 373 is formed, and for example, a conductive oxide typified by a noble metal such as platinum (Pt) or iridium (Ir), or Lanthanum Nickel Oxide (LNO) is preferably used.

On the surface (the surface on the opposite side of the vibration plate 36) of each first electrode 371, a piezoelectric layer 373 and a second electrode 372 are formed individually for each piezoelectric element 37 (each nozzle N). As shown in fig. 8, the second electrodes 372 are laminated on the opposite side of the vibrating plate 36 with respect to the first electrodes 371, and the piezoelectric layers 373 are laminated so as to be sandwiched between the first electrodes 371 and the second electrodes 372. Each of the second electrodes 372 is an electrode extending in the Y direction. Each second electrode 372 is connected to the driver IC62 via a lead electrode 372A drawn out to the outside of the piezoelectric layer 373.

The piezoelectric layer 373 is formed in a patterned manner for each pressure chamber C. As shown in fig. 8, the width of the piezoelectric layer 373 in the X direction is larger than the width of the pressure chamber C (opening 342) in the X direction. Therefore, the piezoelectric layer 373 extends to the outside of the pressure chamber C in the X direction of the pressure chamber C. Therefore, the first electrode 371 is covered with the piezoelectric layer 373 in the X direction of the pressure chamber C.

The piezoelectric layer 373 is a ferroelectric ceramic material exhibiting electromechanical conversion action, such as a crystal film having a perovskite structure (perovskite crystal). The material of the piezoelectric layer 373 is not limited to the above-described materials, and for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT) or a material in which a metal oxide such as niobium oxide, nickel oxide, or magnesium oxide is added can be used.

The second electrode 372 is provided on the surface of the piezoelectric layer 373 opposite to the first electrode 371, and constitutes an independent electrode corresponding to the plurality of piezoelectric elements 37. The second electrode 372 may be provided directly on the piezoelectric layer 373, or another member may be interposed between the piezoelectric layer 373 and the second electrode 372. As the second electrode 372, a material that can form an interface with the piezoelectric layer 373 with good insulating properties and piezoelectric properties is preferably used, and for example, a noble metal material such as iridium (Ir), platinum (Pt), palladium (Pd), or gold (Au), or a conductive oxide typified by Lanthanum Nickel Oxide (LNO) is preferably used. The second electrode 372 may be formed by stacking a plurality of materials.

In the piezoelectric element 37 of the present embodiment, the case where the first electrode 371 is a common electrode for the plurality of piezoelectric elements 37 and the second electrode 372 is an individual electrode corresponding to the plurality of piezoelectric elements 37 is exemplified, but the configuration is not limited to this, and an embodiment may be adopted in which the second electrode 372 is a common electrode for the plurality of piezoelectric elements 37 and the first electrode 371 is an individual electrode corresponding to the plurality of piezoelectric elements 37. Although the case where the diaphragm 36 is formed of a single layer has been described as an example in the above embodiment, the present invention is not limited thereto, and may be formed of a plurality of layers.

Although the pressure chamber substrate 34 and the diaphragm 36 are separately configured in the above embodiment, the present invention is not limited to this, and the pressure chamber substrate 34 and the diaphragm 36 may be integrally formed and the pressure chamber C and the diaphragm 36 may be formed at one time, for example, as in a modification of the third embodiment shown in fig. 10. In the structure of fig. 10, the pressure chamber C and the vibration plate 36 can be formed at one time by selectively removing a portion in the thickness direction of the region corresponding to the pressure chamber C in the single crystal silicon base material of a predetermined thickness in accordance with the above crystal orientation. In the configuration of fig. 10, an adhesion layer 376 for securing adhesion is provided between the piezoelectric element 37 and the diaphragm 36. The adhesion layer 376 of fig. 10 is composed of a silicon oxide film 376A and a zirconium oxide film 376B. The silicon oxide film 376A and the zirconium oxide film 376B are sequentially stacked on the vibration plate 36. Since the adhesion layer 376 has lower toughness than the single crystal silicon constituting the vibration plate 36, the adhesion layer 376 is formed as thin as possible, and as shown in fig. 10, the adhesion layer 376 is not formed at a portion overlapping the arm portion 362b in the direction of the minor axis Gy in a plan view. With this configuration, the arm portions 362b are more likely to be deformed than when the adhesion layer 376 is formed up to the portion where the arm portions 362b overlap in a plan view, and therefore the displacement characteristics of the piezoelectric device 39 can be improved.

Fourth embodiment

A fourth embodiment of the present invention will be explained. In the fourth embodiment, another configuration example of the piezoelectric element 37 of the piezoelectric device 39 according to the first embodiment and the second embodiment will be described. Fig. 11 is a plan view of the piezoelectric device 39 according to the fourth embodiment as viewed from the Z direction. Fig. 12 is a sectional view XII-XII of the piezoelectric device 39 shown in fig. 11.

As shown in fig. 11 and 12, the shape of the inner periphery 345 of the pressure chamber C according to the fourth embodiment is an ellipse having a major axis Gx along the X direction and a minor axis Gy along the Y direction in a plan view. The piezoelectric element 37 according to the fourth embodiment is disposed on the peripheral edge of the pressure chamber C so as not to overlap the center of the pressure chamber C but to overlap the inner periphery 345 of the pressure chamber C in a plan view. Fig. 11 illustrates a case where the entire circumference of the piezoelectric element 37 is formed in a ring shape so as to overlap the entire circumference of the inner circumference 345 of the pressure chamber C in a plan view. However, the piezoelectric element 37 may not overlap the entire circumference of the inner circumference 345 of the pressure chamber C, but may overlap only a part of the inner circumference 345.

The piezoelectric element 37 according to the fourth embodiment is a laminate in which a piezoelectric layer 373 is interposed between a first electrode 371 and a second electrode 372 that face each other. As in the other embodiments described above, the piezoelectric element 37 is configured by a portion where the first electrode 371, the second electrode 372, and the piezoelectric layer 373 overlap in a plan view. The first electrode 371 and the piezoelectric layer 373 shown in fig. 11 are formed on the surface of the vibration plate 36 in the portion of each pressure chamber C so as to overlap the entire circumference of the inner circumference 345 of each pressure chamber C in a plan view. The first electrode 371 and the piezoelectric layer 373 are not formed at the center of the pressure chamber C. The first electrode 371 and the piezoelectric layer 373 are formed on the entire surface of the vibration plate 36 except for the portions of the pressure chambers C. However, the first electrode 371 and the piezoelectric layer 373 may not be formed in the portions other than the portions of the pressure chambers C. The shapes of the inner peripheries of the first electrode 371 and the piezoelectric layer 373 are elliptical in a plan view.

The second electrode 372 is laminated on the opposite side of the vibration plate 36 from the first electrode 371 independently for each piezoelectric element 37 (each nozzle N). The second electrode 372 is disposed so as to overlap the entire inner circumference 345 of each pressure chamber C in a plan view. The inner circumference of each second electrode 372 is elliptical in a plan view, and the outer circumference thereof is substantially rectangular in a longer X-direction than Y-direction. The diaphragm 36 of the fourth embodiment is a single crystal silicon substrate similar to that of the first and second embodiments, and is configured integrally with the pressure chamber substrate 34.

According to the piezoelectric device 39 of the fourth embodiment having such a configuration, by applying a voltage between the first electrode 371 and the second electrode 372, the piezoelectric layer 373 sandwiched between the first electrode 371 and the second electrode 372 is displaced by being subjected to piezoelectric strain. The pressure in the pressure chamber C fluctuates due to the vibration of the vibration plate 36 in conjunction with the piezoelectric deformation of the piezoelectric layer 373. In the fourth embodiment, a portion of the vibration plate 36 that overlaps with the pressure chamber C is a vibration region P.

As shown in fig. 11, since the vibration region P of the fourth embodiment is an ellipse, the minor axis of the smallest rectangle Q shown by a one-dot chain line in fig. 11 including the vibration region P becomes the minor axis Gy of the vibration region P, and the major axis of the smallest rectangle Q including the vibration region P becomes the major axis Gx of the vibration region P. In the fourth embodiment, the major axis of the ellipse constituting the vibration region P is the major axis Gx of the vibration region P, and the minor axis of the ellipse is the minor axis Gy of the vibration region P. By adopting a mode in which the poisson's ratio in the direction of the minor axis Gy of the vibration plate 36 is included in a range of not less than the minimum value of the poisson's ratio in the crystal plane and less than the average value, the same effects as those of the first and second embodiments can be achieved.

Modification examples

The embodiments and examples illustrated above can be modified in various forms. Specific modifications will be exemplified below. Two or more modes arbitrarily selected from the following examples or the above modes may be appropriately combined within a range not contradictory to each other.

(1) Although the serial head in which the carriage 242 on which the liquid ejection head 26 is mounted is repeatedly moved back and forth in the X direction has been exemplified in the above-described embodiment, the present invention may be applied to a line head in which the liquid ejection heads 26 are arranged so as to extend over the entire width of the medium 12.

(2) Although the piezoelectric liquid discharge head 26 using a piezoelectric element that applies mechanical vibration to the pressure chamber has been described as an example in the above embodiment, a thermal liquid discharge head using a heating element that generates bubbles in the pressure chamber by heating may be used.

(3) The liquid ejecting apparatus 10 exemplified in the above embodiments can be used for various apparatuses such as a facsimile machine and a copying machine, in addition to an apparatus dedicated to printing. However, the application of the liquid ejecting apparatus 10 of the present invention is not limited to printing. For example, a liquid ejecting apparatus that ejects a solution of a color material is used as a manufacturing apparatus for forming a color filter of a liquid crystal display device, an organic EL (Electro Luminescence) display, an FED (surface emitting display), or the like. Further, a liquid ejecting apparatus that ejects a solution of a conductive material can also be used as a manufacturing apparatus for forming wiring or electrodes of a wiring board. The present invention can also be used as a chip manufacturing apparatus that discharges a solution of a biological organic substance, which is a kind of liquid.

Description of the symbols

10 … liquid ejection device; 12 … medium; 14 … a liquid container; 20 … control device; 22 … conveying mechanism; 24 … moving mechanism; 242 … carriage; 244 … an endless belt; 26 … liquid ejection head; 32 … flow channel substrate; 322 … supply flow path; 324 … are connected with the flow passage; 326 … intermediate flow passages; 34 … pressure chamber base plate; 342 … opening; 344 … side walls; 345 … inner circumference; 35 … pressure generating part; 36 … diaphragm; 362a … active part; 362b … arm portion; 362c … fixing part; 37 … piezoelectric element; 371 … first electrode; 371a … lead electrode; 372 … a second electrode; 372a … lead electrode; 373 … piezoelectric layer; 376 … next to the layer; 376a … silicon oxide film; 376B … zirconium oxide film; 38 … wiring connection board; 384 … wiring; 385 … wiring; 39 … piezoelectric device; 40 … shell member; 42 … recess; 43 … inlet port; 52 … a nozzle plate; 54 … a flexible substrate; 62 … driver IC; a … first substrate; b … second substrate; a C … pressure chamber; gx … major axis; gy … short axis; l1 … first column; l2 … second column; an N … nozzle; p … vibration region; r … liquid retention chamber; RA … space; RB … space; an S … pressure chamber; h … displacement.

Claims

1. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

a diaphragm disposed between the pressure chamber and the piezoelectric element,

the vibration plate has a crystal face of a single crystal silicon substrate having anisotropy in which Poisson's ratio differs depending on an in-plane direction,

in a vibration region of the vibration plate that overlaps with the pressure chamber in a plan view, a poisson ratio of the vibration plate in a minor axis direction of a smallest rectangle that includes the vibration region is included in a range in which a poisson ratio in the crystal plane is not less than a minimum value but less than an average value.

2. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the monocrystalline silicon substrate is a substrate with a crystal face of {100} plane,

in a vibration region of the vibration plate that overlaps with the pressure chamber in a plan view, a poisson ratio of the vibration plate in a minor axis direction of a smallest rectangle that includes the vibration region is included in a range of not less than a minimum value of poisson ratios in the crystal plane and less than 0.18065.

3. The piezoelectric device according to claim 2,

the poisson's ratio of the vibrating plate in the short axis direction is included in a range of 0.0864 or more from the minimum value of the poisson's ratio in the crystal plane.

4. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the single crystal silicon substrate is a substrate with a crystal face of (100),

in a vibration region of the vibration plate overlapping with the pressure chamber in a plan view, an orientation of a Poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing the vibration region is included in a range from an orientation shifted by 21 degrees toward a crystal orientation [010] to an orientation shifted by 21 degrees toward a crystal orientation [001] with respect to a crystal orientation [011] in the crystal plane.

5. The piezoelectric device according to claim 4,

the orientation of the poisson's ratio of the vibration plate in the short axis direction is included in a range from an orientation shifted by 7 degrees toward crystal orientation [010] to an orientation shifted by 7 degrees toward crystal orientation [001] with respect to crystal orientation [011] in the crystal plane.

6. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the monocrystalline silicon substrate is a substrate with a crystal face being a (010) face,

in a vibration region of the vibration plate that overlaps the pressure chamber in a plan view, an orientation of a poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing the vibration region is included in a range from an orientation shifted by 21 degrees toward a crystal orientation [ -100] to an orientation shifted by 21 degrees toward a crystal orientation [001], with respect to the crystal orientation [ -101] in the crystal plane.

7. The piezoelectric device according to claim 6,

the orientation of the poisson's ratio of the vibration plate in the short axis direction is included in a range of an orientation shifted by 7 degrees toward a crystal orientation [ -100] to an orientation shifted by 7 degrees toward a crystal orientation [001] with respect to a crystal orientation [ -101] in the crystal plane.

8. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the single crystal silicon substrate is a substrate with a crystal face of (001),

in a vibration region of the vibration plate that overlaps the pressure chamber in a plan view, an orientation of a Poisson's ratio of the vibration plate in a minor axis direction of a rectangle that includes the smallest vibration region is included in a range from an orientation shifted by 21 degrees toward a crystal orientation [010] to an orientation shifted by 21 degrees toward a crystal orientation [00-1] with respect to a crystal orientation [ -110] in the crystal plane.

9. The piezoelectric device according to claim 8,

the orientation of the Poisson's ratio of the vibration plate in the short axis direction is included in a range from an orientation shifted by 7 degrees toward crystal orientation [00-1] to an orientation shifted by 7 degrees toward crystal orientation [010] with respect to the crystal orientation [ -110] in the crystal plane.

10. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the single crystal silicon substrate is a substrate with a crystal face of 110,

in a vibration region of the vibration plate overlapping the pressure chamber in a plan view, a poisson's ratio in a minor-axis direction of a smallest rectangle including the vibration region is included, and a minimum value of poisson's ratios in the crystal plane is in a range of greater than or equal to and less than 0.24127.

11. The piezoelectric device according to claim 10,

the poisson's ratio in the short axis direction is included in a range from a minimum value of the poisson's ratio in the crystal plane to 0.1968 or less.

12. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the single crystal silicon substrate is a substrate with a crystal face being a (110) face,

in a vibration region of the vibration plate that overlaps the pressure chamber in a plan view, an orientation of a poisson's ratio of the vibration plate in a short axis direction of a smallest rectangle that contains the vibration region is included in a range of an orientation that is shifted by 7 degrees toward [ -112] from a crystal orientation [ -111] in the crystal plane and is shifted by 20 degrees toward the [ -111] to an orientation that is shifted by 25 degrees toward the [ -112 ].

13. The piezoelectric device according to claim 12, wherein,

the orientation of the Poisson's ratio of the vibration plate in the short axis direction is included in a range of an orientation shifted by 7 degrees toward [ -112] from the crystal orientation [ -111] in the crystal plane, and an orientation shifted by 13 degrees toward the [ -111] to an orientation shifted by 15 degrees toward the [ -112 ].

14. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the single crystal silicon substrate is a substrate with a crystal face of (011),

in a vibration region of the vibration plate that overlaps the pressure chamber in a plan view, an orientation of a poisson's ratio of the vibration plate in a minor axis direction of a smallest rectangle containing the vibration region is included in a range of an orientation shifted from a crystal orientation [1-11] in the crystal plane toward [1-12] by 7 degrees, and an orientation shifted from the crystal orientation [1-11] toward [1-11] by 20 degrees to an orientation shifted from the crystal orientation [1-12] by 25 degrees.

15. The piezoelectric device of claim 14,

the orientation of the Poisson's ratio of the vibrating plate in the minor axis direction is included in a range from an orientation shifted by 7 degrees toward [1-12] from a crystal orientation [1-11] in the crystal plane to an orientation shifted by 13 degrees toward [1-11] to an orientation shifted by 15 degrees toward [1-12 ].

16. A piezoelectric device includes:

a pressure chamber;

a piezoelectric element; and

the single crystal silicon substrate is a substrate with a crystal face of (101),

in a vibration region of the vibration plate that overlaps the pressure chamber in a plan view, an orientation of a poisson's ratio of the vibration plate in a minor axis direction of a rectangle containing the vibration region is included in a range of an orientation shifted from a crystal orientation [11-1] in the crystal plane toward [12-1] by 7 degrees and an orientation shifted from the crystal orientation [11-1] toward [12-1] by 20 degrees to an orientation shifted from the crystal orientation [12-1] toward [12-1] by 25 degrees.

17. The piezoelectric device of claim 16,

the orientation of the Poisson's ratio of the vibration plate in the short axis direction is included in a range from an orientation shifted by 7 degrees toward [12-1] from the crystal orientation [11-1] in the crystal plane to an orientation shifted by 13 degrees toward [11-1] to an orientation shifted by 15 degrees toward [12-1 ].

18. A liquid ejection head in which a liquid ejection head,

a piezoelectric device according to any one of claims 1 to 17,

the liquid filled in the pressure chamber is discharged from a nozzle by oscillating the oscillating plate by the piezoelectric element to vary the pressure of the pressure chamber.

19. A liquid ejection device, wherein,

a piezoelectric device according to any one of claims 1 to 17,